Directly mounted rotary valve on an axial thrust bearing load shaft

ABSTRACT

Directly mounted rotary valve on an axial thrust bearing load shaft, wherein an axial valve tolerance is compensated for by mounting the rotary valve axially between stationary valve wall means and axially constrainable wall means and wherein an axial shaft tolerance is accommodated for by mounting the rotary valve on the load shaft with an axial slidable connection therebetween.

United States Patent [191 Woodling 11] 3,743,450 [451 July 3,1973

[ 4] DIRECTLY MOUNTED ROTARY VALVE ON AN AXIAL THRUST BEARING LOAD SHAFT 1 Invenwn G Y1.WeszsllEaZZQZLWieh Road, Rocky River, Ohio 44116 [22] Filed: Jan. 31, 1972 [21] Appl. No.: 222,096

Related US. Application Data Continuation of Set. Nofl 1,488, Feb, 16, 1970, Pat.

[52] US. Cl 418/61, 251/175, 251/192 [51] Int. Cl Fl6k 25/00, FOlc 1/02, F03c 3/00 [58] Field of Search 418/61', 251/175,

[56] References Cited UNITED STATES PATENTS 5/1970 Waldorff 418/61 3/1971 McDermott 418/61 l/l96l Dudley 251/175 5/1961 Budzich 251/175 3,389,618 McDermott 418/61 3,658,448 4/1972 Woodling 418/61 3,658,450 4/l972 Woodling 418/61 3,592,233 7/197] Woodling 418161 FOREIGN PATENTS OR APPLICATIONS 1,178,893 l/l970 Great Britain 418/61 Primary Examiner-Carlton R. Croyle Assistant Examiner-John .l. Vrablik Attorney-George V. Woodling et al.

[5 7 ABSTRACT Directly mounted rotary valve on an axial thrust bearing load shaft, wherein an axial valve tolerance is compensated for by mounting the rotary valve axially between stationary valve wall means and axially constrainable wall means and wherein an axial shaft tolerance is accommodated for by mounting the rotary valve on the load shaft with an axial slidable connection therebetween 10 Claims, 21 Drawing Figures Pmemimm ams 3.743450 SHEU 2 0F 3 DIRECTLY MOUNTED ROTARY VALVE ON AN AXIAL THRUST BEARING LOAD SI-IAFT BACKGROUND OF THE INVENTION This application is a continuing application of my. prior application, Ser. No. 01 l ,488, filed Feb. 16, 1970 now US. Pat. No. 3,658,450.

A doubleproblem of machine tolerance is encountered when a rotary face valve is directly mounted on an axial thrust bearing load shaft. First, there is a problem of fixing the axial width of the opposing valve faces between which the rotary valves rotates. If the axial valve tolerance is too tight, the rotary valve will turn hard and create excessive friction and heat. On the other hand, if the axial valve tolerance is too loose, the rotary valve will leak and cause inefficient valve operation. A second problem of machine tolerance arises in fixing the axial position of the load shaft relative to that of the rotary valve, which is indeterminable prior to the time that the rotary valve is mounted on the shaft. It is found that exactness is machine tolerance is substantially impossible to maintain on a production basis.

Accordingly, it is an object of my invention to compensate for axial valve tolerance and to accommodate for axial shaft tolerance.

Another object is to compensate for axial valve tolerance by mounting the rotary valve axially between statioary valve wall means and axially constrainable wall means.

Another object is to accommodate for axial shaft tolerance by mounting the rotary valve on the load shaft with an axial slidable connection therebetween.

SUMMARY OF THE INVENTION The invention constitutes valve and shaft mounting means, including rotary valve means axially disposed between first and second facing wall means, said first facing wall means constituting stationary valve wall means, said second facing wall means constituting axially constrainable wall means to compensate for axial valve tolerance, said rotary valve means having first side wall means sealingly engaging said stationary valve wall means and having second side wall means against which said axially constrainable wall means engages for urging said first side wall means of said rotary valve means against said stationary valve wall means, shaft means rotatively for supporting said rotary valve means, bearing means for said shaft means and including axial thrust bearing means for fixing the axial position of said shaft means relative to said rotary valve means, non-rotative connection means between said shaft means and saidrotary valve means, whereby rotation of said shaft means rotates said rotary valve means, said non-rotative connection means including axially slidable engagement means to accommodate for axial shaft tolerance between said rotary valve means and said shaft means.

Other objects and a fuller understanding of the invention may be had by referring to the following description and claims, taken in conjunction with the accompanying drawings, in which:

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 2 is a longitudinal sectionalview of FIG. 1, the

second being taken along a line 2-2 of FIG. 10, except that the sectional view, for clarity, is taken as if it were extended through both of the fluid port means which are located on opposite sides of the longitudinal section;

FIG. 3 is a representation of a male shank provided on a terminal end portion of a hollow shaft adapted to slidably fit within a emale socket of the rotary body means, the male shank being rotated degrees from the position shown in FIG. 2 to show the interfitting flat pads on opposite sides thereof;

FIG. 4 is an end view of the hollow male shank of FIG. 3;

FIG. 5 is a cross-sectional view of FIG. 2, taken along the line 513 5 thereof and showing principally an annular confronting face of a stationary reaction wall; 5-

FIG. 6 is a left-hand end view of the face only of the bushing in FIG. 2, taken along the line 6-6 thereof;

FIG. 7 is a left-hand side view of a stationary valve in FIG. 2, taken along the line 7-7 thereof, showing principally a plurality of circumferentially disposed fluid valve openings therein and constituting fluid valve area-way means;

FIG. 8 is a right-hand end view of the face only of the bushing which is non-rotative, the view being taken along the line 8-8 of FIG. 2 and shows principally a plurality of circumferentially disposed fluid balancing pattern area-way recesses provided in the face of the bushing, and being in substantially straight axial alignment with the fluid valve area-way means in FIG. 7 to create fluid balancing forces in opposition to those created by the valve area-way means;

FIG. 9 is a right-hand side view of the face only of the rotary body means, taken along the line 9-9 of FIG. 2, showing principally the rotary valve face which confrontingly engages the stationary valve face of FIG. 7;

FIG. 10 is a left-hand side view of the face only of the rotary body means, taken along the line 10-10 of FIG. 2, showing principally the rotary pattern face which confrontingly engages the balancing non-rotative pattern face of FIG. 8;

FIG. 11 is a cross-sectional view of the rotary body means of FIG. 10, taken along the line 11-11 thereof;

FIG. 12 is a cross-sectional view of the rotary body means of FIG. 10, taken along the line 12-12 thereof;

FIG. 13 is an enlarged sectional view of the axialthrust bushing in FIG. 2, and shows a modification, in that the diameter of the left-hand flange is somewhat smaller than that for the right-hand flange to give a resultant piston-effect to produce an axial thrust;

FIG. 14 is a view similar to FIG. 2, showing a modification of the rotary body means and the axial-thrust bushing;

FIG. 15 is a left-hand end view of the face only of the bushing in FIG; 14, taken along the line 15-15 thereof;

FIG. 16 is a right-hand end view of the face only of the bushing in FIG. l4, taken long the line 16-16 thereof;

FIG. 17 is a right-hand side view of the face only of the rotary body means of FIG. 14, taken along the line 17-17 thereof, the opposite side of the rotary body means being identical thereto;

FIG. 18 is a left-hand side view of the stationary valve face in FIG. 14, taken along the line 18-18 thereof; FIG. 19 is an enlarged sectional view of the axialthrust bushing of FIG. 14; and,

FIGS. 20 and 21 show principally split stop pin means.

DESCRIPTION OF THE PREFERRED EMBODIMENT The fluid pressure device in which my invention may be incorporated may comprise a fluid motor, a fluid pump, a fluid transmission, a fluid servomotor and/or any other related device.

The fluid pressure operating means may be of the type usually referred to in the trade as a stator-rotor orbital mechanism, and may be the same as that shown in my U.S. Pat. No. 3,405,603.

In this application, the term stator and rotor are not used in a limited sense. The term stator is applied to the element which has a fixed axis and the term rotor is applied to the element which has a movable axis characterized in that said rotor is disposed for rotational movement about its own movable axis and for orbital movement about the fixed axis of the stator. Thus, in this application, the outer surrounding element, usually referred to as the stator, may be either the stator or the rotor, depending upon whether it has a fixed axis or a movable axis and the inner element, usually referred to as the rotor, may be either the rotor or the stator depending upon whether it has a movable axis or a fixed axis.

For clarity of invention, the usual static seals and the seal for the rotating shaft are not shown. Also, all wear parts are made of hardenable surfaces and are well lubricated by the operating fluid.

With reference to the drawing, the fluid pressure device in which my invention may be incorporated, comprises generally a main housing 20 having substantially a square cross-section. A mounting flange 21 may be secured to the left-hand end of the housing by means of suitable screws 26 (one of which is shown in FIG. 1). The housing 20 is hollow from end-to-end, and intermediate the ends of the hollow housing there is provided an annular internal rim 22 which generally separates the hollow-housing into a left-hand end compartment and a right-hand end compartment. Rotatively mounted in the left-hand end compartment is a main load shaft 25 having an axis substantially coinciding with the longitudinal axis of the fluid pressure device. An axial-thrust bushing 27 and a rotary body 28 are mounted in the right-hand end compartment. On the right-hand end of the hollow housing, there is mounted a square stationary valve member 29 by means of suitable screws 30. The rotary body is adapted to be rotated relative to the stationary valve member 29 for controlling the entrance of fluid to and the exit of fluid from a stator-rotor mechanicam 31 comprising a stator 32 and a rotor 33. An end cap 34 encloses the statorrotor mechanism 3l. The stator-rotor mechanism. 31

and theend cap 34 are secured to the stationary valve member 29 by means of screws 35. Fluid is delivered to and from the housing 20 through a pair of fluid ports 23 and 24. An interconnecting shaft 36 interconnects the main shaft 25 with the rotor 33 of the stator-rotor mechanism 31 and is adapted to transmit torque therebetween.

The main shaft 25 comprises an enlarged internal portion having a reduced external portion 41 extending axially outwardly of the main housing 20 through the mounting flange 21. The enlarged internal portion of the main shaft is supported preferably by tapered roller bearings 42 and 43 disposed side-by-side with the bearing 42 disposed oppositely to that of the tapered roller bearing 43. Thus, the tapered roller bearings 42 and 43, in combination with each other, provide for radial thrust as well as for end thrust in both axial directions, with the tapered roller bearing 42 disposed to take the greater part of the radial load. A tightening nut 54 which threadably engages male threads 55 secures the bearings 42 and 43 against axial movement upon the main shaft. The tightening nut 54 may be provided with a builtin locking feature to prevent loosening.

As shown, the bearings 42 and 43 are secured against axial movement in the housing by axial fixation means, indicated by the reference character 60. The axial fixation means 60 is located within a bore 62 of the flange and comprises an annular V-shaped or pointed rib which axially abuts against a transversely disposed solid abutment wall of the bearing 42. The rib may be constructed either integrally with or as a separate part from the flange 21. By pressing the flange 21 against the end of the housing 20 during assembly, the pointed rib is coined against the bearing 42, with the result that the fixation means accommodates for axial tolerance in matching the position of the hearings in the housing. The pressure required to coin the axial fixation means is greater than the end-wise thrust load to which the bearing means 42 may be subjected in operation, in which case the bearings 42 and 43 are resisted against axial movement in operation. The main shaft is entirely supported by the two tapered roller bearings 42 and 43. The reduced external shaft portion 41 where it passes axially through the end mounting flange 21 is not journalled therein but rotates therein with a small radial clearance which is adapted to be sealed off by suitable shaft seal means, not shown. The axial fixation-means 60, after being coined, provides a fluid seal between the housing and the flange.

The bearings 42 and 43 constitute common bearing means for the main shaft 25 and the rotary body 28. The common bearing means directly support the main shaft 25 and indirectly support the rotary body 28 through extension drive means comprising a hollow shaft 44 carried by the load shaft 25. The hollow shaft 44 extends axially from the load shaft 25 in the lefthand compartment into the right-hand compartment for driving connection with the rotary body 28 for rotating same relative to the stationary valve 29. The hollow shaft 44 terminated with a male shank 45 which slidably fits within a female socket 46 provided in the rotary body 28, see FIGS. 10 and 12. This connection comprises a non-rotatable connection and rotates the rotary body upon rotation by the main shaft. The connection also provides slidable axial movement between the rotary body 28 and the hollow shaft 40 to accommodate for axial movement of the load shaft without interfering with the operation of the rotary body 28. Tile axial slidable movement which is permitted between the male shank 45 and the female socket 46 is greater than the maximum distance that the load shaft 25 may move in an axial direction during operation. As illustrated in FIGS. 2 and 13, the rotary body 28 and thesecond compartment means in which it is mounted has a radial clearance 47 therebetween to accommodate for radial movement of the load shaft 25 without interfering with the operation of the rotary body. The

radial clearance 47 is greater than the maximum distance that the load shaft 25 may movein a radial direction during operation. The radial clearance 47 also extends between the bushing 27 and the main housing 20. The rotary body 28 has first and second opposed body sides or flanges 56 and 57, see FIGS. 11 and 12. As shown, the rotary body 28 has generally an H-shaped cross section with the flanges 56 and 57 being interconnected by an annular cross-bar 61. The first opposed body side or flange 56 constitutes a rotary valve 39 having a rotary valve face 40 (FIG. 9) which confrontinly engages a stationary valve face 37 of the stationary valve 29. The second opposed body side or flange 57 constitutes rotary pattern means 51 having a rotary pattern face 52 (FIG. which is axially spaced from, and which faces, a stationary reaction wall 64, see FIGS. 2 and 5.

The operation of the rotary valve 39 relative to the stationary valve 29 provides for controlling the entrance of fluid to and the exit of fluid from the statorrotor mechanism. The action of the rotary valve 39 in commutation with the stationary valve 29 is such that there is a first series of commutating fluid connections between the fluid port 23 and the stator-rotor mechanism and a second series of commutating fluid connections between the stator-rotor mechanism and the fluid port 24. The stationary valve 29 has a plurality of circumferentially disposed openings 48 which extend therethrough to provide for fluid communication between the rotary valve 39 and the stator-rotor mechanism. The commutating valve action, and the flow of fluid between the fluid ports 23 and 24 and the statorrotor mechanism is substantially the same as that shown and described in my US. Pat. No. 3,405,603. Thus, in the present application, the annular external channel 58 around the outside of the rotary valve constitutes a first fluid chamber and is in constant communication with the fluid port 23 and the central space or internal channel 59 inside the rotary valve constitutes a second fluid chamber and is in constant communication with the fluid port 24 through opening means 50 in the hollow shaft 44.

As shown and described in the present disclosure, the rotary valve 39 functions without interference from axial and radial thrust loads on the load shaft 25, even though it is rotatively supported by the same bearings that support the load shaft.

In the present invention, the rotary valve face 40 is axially constrained against the stationary valve face. 37 by the axial-thrust bushing 27. TI'Iis constraining action prevents fluid leakage between the rotary valve face and the stationary valve face. As shown in FIGS. 2, and 5 to 13, the axial-thrust bushing 27 is mounted between the stationary reaction wall 64 and the rotary pattern face 52, and is held against rotation by stop pin means 65 which interconnects the stationary reaction wall 64 and the bushing 27. One end of the stop pin 65 fits into a hole 66 in the stationary reaction wall 64. and the other end of the stop pin fits into a hold 67 in the bushing 27. i

The bushing 27 has first and second end portions 68 and 69 (see FIG. 13), andhas generally an 'H-shape cross-section including first and second axially spaced flange legs 70 and 71 and an interconnecting annular cross-bar 72. The flange legs 70 and 71 each have an outer flange leg portion with inside opposing faces 73 and 74 defining an external fluid channel around the cross-bar 72. Also, each of the flange legs 70 and 71 have an inner flange leg portion with inside opposing faces 75 and 76 defining an internal fluid channel within the annur cross-bar 72. The flange leg comprises non-rotative pattern means 77 having a nonrotative pattern face 78 (FIG. 8) confrontingly engaging the rotary pattern face 52 (FIG. 10). The rotary body 28 is disposed between the stationary valve face 37 and the non-rotat ve pattern face 78. The flange leg 71 is resilient and has an outer annular rim portion 80 and an inner annular rim portion 81 with an annular restraint portion 79 therebetween, which is integrally connected to the cross-bar 72. The outer and inner rim portions 80 and 81 confrontingly engage the stationary reaction wall 64 with the annular restraint portion 79 spaced from and yieldably movable in an axial direction relative to the stationary reaction wall 64. The annular restraint portion 79 defines with the stationary reaction wall 64 a space chamber 63 and the restraint portion 79 is under restraint for transmitting an axial resilient force through the cross-bar 72 to resiliently urge the rotary valve face 40 against the stationary valve face 37 to prevent fluid leakage. The outer and inner annular rim portions 80 and 81 make a metal-tometal engagement with the stationary reaction wall 64 and act as metal fluid seals to prevent pressurized fluid from entering into and from otherwise pressurizing the space chamber 63. Thus, the piston effect of the space chamber 63 is substantially nullified. The opposing faces 73 and 74 and the opposing faces and 76 of the outer and inner flange legs portions respectively are yieldingly spreadable relative to each other in an axial direction under influence of pressurized fluid and respectively constitute pressure responsive means for transmitting a fluid force to urge the rotary valve face 40 against the stationary valve face 37. The opposing faces 73 and 74 are in constant fluid communication with the fluid port 23 and the opposing faces 75 and 76 are in constant fluid communication with the fluid port 24.

The amount of the axial thrust of the bushing 27 for urging the rotary body 28 against the stationary valve 29 is, of course, determined by the leakage factor. It need not be any greater than that required to prevent excessive leakage. If the axial thrust is too great, it may impose an excessive drag on the rotation of the rotary body. The axial thrust may be calibrated to the correct value by providing a piston-effect to the bushing in addition to the combined forces of the resilient flange 71 and the pressure responsive means. The piston-effect may be provided by making the effective diameter of the resilient flange 71 less than the effective diameter of the right-hand flange 70, such as is shown in FIG. 13, being in contrast to that shown in FIG. 2, where the diameters are substantially the same. The diameters may be readily varied in manufacture to provide the correct calibrated piston-effect. The amount that the resilient flange 71 is under axially restrain may be in the other of approximately 0.005 inch to accommodate for wear.

in the present invention, the rotary body 28 is axially balanced hydraulically between the stationary valve face 37 and the non-rotative pattern face 78 by pressure balancing pattern means including a plurality of area-way recesses 82 extending from the pattern face 78. Preferably, the area-way recesses 82 are directly in straight axial alignment with the plurality of fluid openings 48 defining valve area-way in the face 37.of the stationary valve 29. The size and shape of the pattern area-way means or recesses 82 are disposed to match the size and shape of the fluid opening 48 which constitute the valve area-way means, whereby hydraulically they create substantially equal and opposite balancing forces to balance the rotary body 28 between the stationary valve face 37 and the nonrotative pattern face 78.

In my invention, the valve system means, which comprises the rotary valve 39 and the stationary valve 29, is disposed to provide a first series of commutating fluid connection means between the first fluid port 23'and the expanding fluid chambers in the stator-rotor mechanism and a second series of commutating fluid connection means between the contracting fluid chambers in the stator-rotor mechanism and the second fluid port 24. To this end, the stationary valve 29 has seven fluid openings 48 (FIG. 7) communicating respectively with the spaces between the internal teeth of the stator element. The first series of commutating connection means comprise six fluid slot means 83 in constant fluid communication with the first fluid port 23. The second series of commutating fluid connection means, likewise comprising six fluid slot means, are identified by the reference character 84 and are in constant fluid communication with the second fluid port 24.

In operation as a fluid motor, high pressure fluid from the high pressure port 23 commutatively flow through the first series of commutating fluid connection means 83 of the rotary valve into the fluid openings 48 of the stationary valve 29 and thence into the expanding pressure fluid chambers in the stator-rotor mechanism and drives the rotor 33 within the stator 32. As the rotor is driven, the exhaust fluid in the low pressure contracting chambers commutatively flows through the fluid openings 48 of the stationary valve 29 into the second series of fluid commutating connection means 84 of the rotary valve and thence to the low pressure port 24. As the rotor is driven by the high pressure fluid, it operates the main shaft 25 through the interconnecting shaft 36.

The registration of the fluid connection means 83 and 84 provided by the rotating valve face 40 in sealing engagement with the stationary valve face 37 is such that there is a first series of commutating fluid connections between the high pressure port 33 and the expanding fluid chambers in the stator-rotor mechanism and a second series of commutating fluid connections between the contracting fluid chambers and the low pressure port 24.

The pressure balancing pattern means operates in substantially the same manner as that described with reference to the first and second series of fluid conduction means 83 and 84, and to this end, the rotary pat tern face 52 (FIG. is provided with six slot means 85 and 86 characterized as first and second series of fluid transit means. The first series of fluid transit means 85 communicatingly interconnect the fluid port 23 (pressurized fluid) with the area-way recesses 82 and the second series of fluid transit means 86 communicatingly interconnect the area-way recesses 82 (exhaust fluid) with the fluid port 24. Thus, the pattern area-way recesses 82' provides an axial fluid force which directly opposes the axial fluid force created by the valve area-way means 48 to hydraulically balance the rotary body 28. As shown, the rotary pattern face 52 (FIG. 10) and the rotary valve face 40 (FIG. 9) are identical, except for the female socket 46, but this difference is slight and does not affect the axial hydraulic balancing of the rotary body 28. The rotary pattern face 52 and the rotary valve face 40 are identical in all other respects. Thus, the view taken along the line 2-2 of FIG. 10 and shown in FIG. 2, shows like sections on opposite sides of the longitudinal center-line. Similarly, the view taken along the line 11-11 of FIG. 10 and shown in FIG. 11, shows like sections on oppoiste sides of the longitudinal center-line. The line 12-12 of FIG. 10 passes through the lands between the slots and 86 and the sections shown thereby in FIG. 12 are alike on opposite sides of the longitudinal center-line.

FIGS. 14 to 19 show a modification of the axial thrust bushing and the rotary body, now identified by the reference characters 87 and 88, respectively. Like parts in FIGS. 14 to 19 to those in FIGS. 1 to 13 are identified by the same reference characters and the description with reference to FIGS. 1 to 13 apply equally well to the FIGS. 14 to 19. H-shaped The rotary body 88 comprises a flat disk and opposing body sides are identical. A right-hand body side is shown in FIG. 17 and constitutes a rotary valve having a rotary valve face 89 (FIG. 17) confrontingly engaging the stationary valve 29. The opposite body side constitutes a rotary pattern having a rotary pattern face 90 confrontingly engaging a non-rotative pattern face 91 (FIG. 16) constituting the right-hand end face of the bushing 87. As shown in FIG. 14 and 19, the bushing 87 has generally an H-Shaped cross-section, but is wider than the bushing 27, providing an enlarged external annular fluid channel 94 and an enlarged internal fluid channel 95. The right-hand face 91 of the bushing 87 (FIG. 16) is provided with six fluid slots 96 which communicate with the external fluid channel 94 and with six fluid slots 97 which communicate with the internal fluid channel 95. The fluid slots 96 and 97 have equal areas and constitute open pattern area-way means which oppose the valve area-way means 48 in the stationary valve 29. The area of the respective slots 96 and 97 are equal and each have an area equal to the area of each of the valve area-way means 48.

The rotary body 88 has six outside slots 98 and six inside slots '99. The portion of the slots 98 where they pass through the rotary valve face 89 may be designated as the first series of fluid conduction means and the portion of the slots 99 where they pass through the rotary valve face 89 may be designated as the second series of fluid conduction means. The registration of the first and series of fluid conduction means with the valve area-way openings 48 provide for controlling the flow of fluid to and from the stator-rotor mechanism. The portion of the slots 98 where they pass through the rotary pattern face 90 (body side opposite to that shown in FIG. 17) may be designated as the first series of fluid transit means and the portion of the slots 99 where they pass through the rotary pattern face 90 may be designated as the second series of .fluid transit means. Thus, the first series of fluid transit means and the first series of fluid conduction means provide for through conduction of fluid from the external fluid channel 94 to the stationary valve 29. Similarly, the second series of fluid transit means and the second series of the fluid conduction means provide for through conduction of fluid from the internal fluid channel to the stationary valve 29. The fluid pressure thrust acting upon the left-hand body side of the rotary body 88 in FIG. 14 through the slots 96 is substantially equal to and opposes the fluid pressure thrust acting upon the right-hand body side of the rotary body 88 through the valve area-way means 48. The fluid slots 97 act in a corresponding way but provide for exhaust fluid. As shown in FIG. 19, thediameter of the resilient flange 71 may be somewhat smaller than the diameter of the flange 70 to provide a piston-effect to give a calibrated value to the axial thrust of the bushing 87. In FIG. 14, the diameters of the flanges 70 and 71 are the same. Thus, it is seen that the bushing 87 and the rotary body 88 operate to provide substantially the same results as that provided by the bushing 27 and the rotary body 28.

The two stop pins 65 which fit in the holes 66 and 67 are shown as being solid and extend into the cross-bar of the bushing. They have a diameter which is smaller than the thickness of the cross-bar,see FIGS. 6 and 15, and there is no leakage of fluid into the space chamber 63. This construction nullifies any piston-effect which would otherwise occur if the space chamber 63 were pressurized. If full fluid fluid pressure were admitted to the space chamber 63. The piston-effect would excessively overpower the piston-effect produced between the rotary valve face and the stationary valve face due to leakage fluid therebetween. An excessive overpowering of the leakage piston-effect between the rotary valve face and the stationary valve face would impose too heavy a drag against rotation of the rotary valve relative to the stationary valve. However, the space chamber 63 may be moderately pressurized to produce a reduced piston-effect to aid in axially balancing the rotary valve face against the stationary valve face. To this end, the two s'top pins may be split, one of which being shown in FIG. 20 and being identified by the reference character 49. The split pins may comprise split dowel pins which are readily available on the market. For moderate pressurization of the space chamber 63, the two split pins are located where the two circles 53 are shown in FIGS. 6 and 15 and illustrated by the fragmentary views in FIG. 21, whereby they provide a restricted interleakage of fluid into the space chamber 63 from either one of the two annular fluid chamber extending externally around or internally within the annular cross-bar, depending upon which is pressurized. Let it be assumed that the external annular chamber is pressurized and under this situation, fluid flows through the split pin located outwardly of the annular cross-bar into the space chamber 63, from whence it flows through the split pin located inwardly of the annular cross-bar into the internal annular chamber. The width or gap of the space chamber 63 may be in the order of approximately 0.0lO-inch (being sufficient to accommodate for the axial restraint of the resilient flange 71) and thus the orifice provided by the split pin in association with the .010 inch space gap is relatively small. The amount of the restriction of the orifice may be varied by varying the width of the space gap. In practice, the orifices of the twosplit pins are substantially the same so as to provide a moderate pressurization of the space chamber 63. The fluid flows into the space chamber 63 through substantially the same amount of restriction as it flows out of the space chamber. This action produces a reduced fluid pressure in the space chamber. This action is the same, but reversed, when the internal annular chamber is pressurized. Of course, the solid stop pins need not be used when the split pins are used, and vice versa. The fluid in the space chamber may be characterized as leakage space fluid and the piston effect produced thereby is sufficient to over-power the piston effect produced by leakage fluid between the rotary valve face and the stationary valve face. Thus, leakage space fluid is utilized to prevent leakage fluid between mutually engaging the valve faces.

Although this invention has been described in its preferred form with a certain degree of particularity, it is understood that the present disclosure of the preferred form has been made only by way of example and that numerous changes in the details of construction and the combination and arrangement of parts may be resorted to without departing from the spirit and the scope of the invention as hereinafter claimed.

What is claimed is:

1. Valve and shaft mounting means, including rotary valve means axially disposed between first and second facing wall means, said first facing wall means constituting stationary valve wall means, said second facing wall means constituting axially constrainable wall means to compensate for axial valve tolerance, said rotary valve means having first side wall means sealingly engaging said stationary valve wall means and having second side wall means against which said axially constrainable wall means engages for urging said first side wall means of said rotary valve means against said stationary valve wall means, shaft means rotatively for supporting said rotary valve means, bearing means for said shaft means and inluding axial thrust bearing means for fixing the axial position of said shaft means relative to said rotary valve means, said rotary valve means including external wall means around which fluid may flow and internal wall means defining internal valve fluid chamber means, said shaft means including hollow shaft body means defining internal shaft fluid chamber means in constant fluid communication with the internal valve fluid chamber means, said hollow shaft body means having passage wall means through which fluid may flow to and from said internal shaft fluid chamber means, non-rotative connection means between said shaft means and said valve means, whereby rotation of said shaft means rotates said rotary valve means, said non-rotative connection means including axially slidable engagement means to accommodate for axial shaft tolerance between said rotary valve means and said shaft means.

2. The structure of claim 1, wherein said rotaryvalve means has female socket means and wherein said shaft means has male boss means, said female socket means and said male boss means comprising interfitting parts and constituting said non-rotative connection means.

3. The structure of claim 1, including reaction face wall means axially spaced from said stationary valve wall means, and axially constrainable means between said reaction face wall means and said rotary valve means.

4. The structure of claim 3, wherein said axially constrainable means includes bushing means having first and second end portions, said first end portions engaging said reaction wall'means and said second end portion engaging said second side wall means of said rotary valve means.

5. The structure of claim 4, wherein one of said end portions is axially constrainable.

6. The structure of claim 4, wherein one of said end portions includes an axially constrainable annular flange.

means and an interconnecting annular cross-bar, said first flange means engaging said reaction face wall means and said second flange means engaging said second side wall means of said rotary valve means.

9. The structure of claim 8, wherein one of said flange means is axially constrainable.

10. The structure of claim 8, wherein said first flange means is axially constrainable.

III l Ill t 

1. Valve and shaft mounting means, including rotary valve means axially disposed between first and second facing wall means, said first facing wall means constituting stationary valve wall means, said second facing wall means constituting axially constrainable wall means to compensate for axial valve tolerance, said rotary valve means having first side wall means sealingly engaging said stationary valve wall means and having second side wall means against which said axially constrainable wall means engages for urging said first side wall means of said rotary valve means against said stationary valve wall means, shaft means rotatively for supporting said rotary valve means, bearing means for said shaft means and including axial thrust bearing means for fixing the axial position of said shaft means relative to said rotary valve means, said rotary valve means including external wall means around which fluid may flow and internal wall means defining internal valve fluid chamber means, said shaft means including hollow shaft body means defining internal shaft fluid chamber means in constant fluid communication with said internal valve fluid chamber means, said hollow shaft body means having passage wall means through which fluid may flow to and from said internal shaft fluid chamber means, non-rotative connection means between said shaft means and said rotary valve means, whereby rotation of said shaft means rotates said rotary valve means, said non-rotative connection means including axially slidable engagement means to accommodate for axial shaft tolerance between said rotary valve means and said shaft means.
 2. The structure of claim 1, wherein said rotary valve means has female socket means and wherein said shaft means has male boss means, said female socket means and said male boss means comprising interfitting parts and constituting said non-rotative connection means.
 3. The structure of claim 1, including reaction face wall means axially spaced from said stationary valve wall means, and axially constrainable means between said reaction face wall means and said rotary valve means.
 4. The structure of claim 3, wherein said axially constrainable means includes bushing means having first and second end portions, said first end portion engaging said reaction wall means and said second end portion engaging said second side wall means of said rotary valve means.
 5. The structure of claim 4, wherein one of said end portions is axially constrainable.
 6. The structure of claim 4, wherein one of said end portions includes an axially constrainable annular flange.
 7. The structure of claim 4, wherein said first end portion of said bushing means includes an axially constrainable annular flange.
 8. The structure of claim 1, including reaction face wall means axially spaced from said stationary valve wall means, bushing mEans between said reaction face wall means and said rotary valve means, said bushing means comprising generally an H-shaped cross-section and including first and second axially spaced flange means and an interconnecting annular cross-bar, said first flange means engaging said reaction face wall means and said second flange means engaging said second side wall means of said rotary valve means.
 9. The structure of claim 8, wherein one of said flange means is axially constrainable.
 10. The structure of claim 8, wherein said first flange means is axially constrainable. 